source: src/AST/Bitfield.hpp @ 9a0cd9c

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Bitfield.hpp --
//
// Author           : Aaron B. Moss
// Created On       : Thu May 9 10:00:00 2019
// Last Modified By : Aaron B. Moss
// Last Modified On : Thu May 9 10:00:00 2019
// Update Count     : 1
//

#pragma once

#include <strings.h>  // for ffs

/// Make a type a bitfield.
/// Include in type definition to add operators. Used to simulate inheritance because union
/// does not allow it. Requires type to have `unsigned val` field
/// @param BFType  Name of containing type
template<typename T>
struct bitfield : public T {
        static_assert(sizeof(T) == sizeof(unsigned int), "Type has incorrect size");
        using T::val;
        using val_t = decltype(val);

        constexpr bitfield() : T( 0 ) {}
        constexpr bitfield( val_t v ) : T( v ) {}

        bool operator[]( val_t i ) const { return val & (1 << i); }
        bool any() const { return val != 0; }
        void reset() { val = 0; }
        int ffs() { return ::ffs( val ) - 1; }

        bitfield operator&=( bitfield other ) {
                val &= other.val; return *this;
        }
        bitfield operator&( bitfield other ) const {
                bitfield q = other;
                q &= *this;
                return q;
        }
        bitfield operator|=( bitfield other ) {
                val |= other.val; return *this;
        }
        bitfield operator|( bitfield other ) const {
                bitfield q = other;
                q |= *this;
                return q;
        }
        bitfield operator-=( bitfield other ) {
                val &= ~other.val; return *this;
        }
};

/// Adds default printing operator to a bitfield type.
/// Include in definition to add print function, requires other bitfield operators.
/// @param N  Number of bits in bitfield
#define MakeBitfieldPrint( N ) \
        static const char* Names[]; \
 \
        void print( std::ostream & os ) const { \
                if ( (*this).any() ) { \
                        for ( unsigned int i = 0; i < N; i += 1 ) { \
                                if ( (*this)[i] ) { \
                                        os << Names[i] << ' '; \
                                } \
                        } \
                } \
        }

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //